Early Tuesday, after a 21-month investigation, Anthony P. Bosch, the businessman at the center of the South Florida doping scandal, surrendered to Drug Enforcement Administration agents.

Prosecutors charged the former Biogenesis of America owner and a half-dozen of his associates with distributing a controlled substance — the anabolic steroid testosterone — to hundreds of people, including high school athletes and multimillionaire superstars.

“Our investigation revealed that these performance-enhancing drugs did go to minors, to professional athletes and to others,” Wifredo A. Ferrer, the US attorney for the Southern District of Florida, said in a phone interview. “It was a network of recruiters and folks in the black market.”

But even before his arrest, Bosch, 50, had already struck a deal with prosecutors to help them expose his network, much like he had helped Major League Baseball a year earlier make its case against Alex Rodriguez. This time, in exchange for Bosch entering a guilty plea and providing information for investigators, prosecutors agreed to recommend a lenient sentence. Bosch faces 10 years in prison.

Get Sports Headlines in your inbox:

The Globe's most recent sports headlines delivered to your inbox every morning.

On Tuesday, a seven-page court filing outlined the information that Bosch could share with prosecutors. The document names a number of Bosch’s colleagues — a series of patient recruiters, business partners, and suppliers — who were also charged in the case Tuesday.

Beginning in October 2008, Bosch began offering testosterone and other chemicals to patients at the anti-aging clinics he co-founded in South Florida. He was known to wear a white lab coat and refer to himself as “Dr. T,” leading most of his customers to believe that he was a doctor. But Bosch had no medical credential of any sort.

“The clinics’ customers were not only ordinary people who just wanted to improve their physical appearance, but also others with different motives, professional baseball players [or athletes], minor league players, and college and high school baseball players who wanted to increase their athletic prowess by using performance-enhancing drugs,” the court document said.

To obtain the drugs, Bosch forged prescriptions and scoured the black market.

Some of his patients were high school students, ages 15 to 17, who would visit him with their parents. They paid $260 to $600 per month for the drugs. Prosecutors said Bosch admitted to treating at least 18 minors.

“He is not a doctor,” said Mark R. Trouville, the Drug Enforcement Administration’s special agent in charge in Miami. “He is a drug dealer.”

At the same time, Bosch was also treating professional athletes, advising them that “he could make them feel better, get stronger, recover faster, and play better” — and that his treatment regimen, which included preloaded testosterone syringes — was “safe and undetected if used exactly as prescribed,” the document said. The professionals paid up to $12,000 a month.

Joyce Fitzpatrick, a spokeswoman for Bosch, said that Bosch regretted his actions.

“Tony Bosch recognizes that he has made mistakes in the past and has spent the past year working hard to correct those mistakes,” she said in a statement. “Mr. Bosch looks forward to putting this chapter of his life behind him and moving forward in a positive way.”

In March 2011, Bosch and two of his associates formed a company called Scores Sports Management, Inc., according to the prosecutor’s office. The company took pre-loaded syringes of testosterone to the Dominican Republic for aspiring baseball prospects, ages 12 to 17, who were preparing for the baseball draft.

Bosch continued to dispense performance-enhancing drugs until late 2012, a short time before the Miami New Times, a weekly newspaper, reported that it had obtained documents from Bosch’s clinic, potentially connecting a number of players to the use of banned substances.

Early in the case, MLB investigators went to Florida to meet with DEA agents who had been looking at Biogenesis. The Florida Department of Health also looked into Bosch last year, initially fining him $5,000 for impersonating “a medical doctor by diagnosing and treating patients.”

Bosch originally denied giving performance-enhancing drugs to ballplayers, but he later changed his story, becoming MLB’s star witness against Rodriguez. In exchange for his cooperation, baseball officials agreed to pay for Bosch’s security, lawyers, and to tell the Department of Justice about his assistance.

Investigators said Tuesday that they had been looking at Bosch, separately from the MLB case.

Late last year, Bosch took the witness stand as Rodriguez appealed his doping ban, the sport’s longest for doping. During a contentious hearing in New York, Bosch offered testimony that led to Rodriguez’s being barred for all of the 2014 season and postseason. With Bosch’s assistance, MLB also suspended 13 other players, including stars such as Ryan Braun and Nelson Cruz.

At the height of the doping controversy, lawyers for Rodriguez sought to discredit Bosch as a witness, pointing to the assistance he was receiving from MLB in exchange for his cooperation.

On Tuesday, Joe Tacopina, a lawyer for Rodriguez, said, “At the end of the day, Alex was not charged with a crime.”

As for Bosch, Tacopina said, “The day has finally come when that stupid smirk gets wiped off his face.”

Although Rodriguez was not charged, Yuri Sucart, his cousin and longtime associate, was also arrested Tuesday. Sucart has been barred from major league clubhouses for several years.

In 2009, when Rodriguez admitted that he had used steroids earlier in his career, he said that Sucart, 52, had gotten the substances for him from the Dominican Republic. Other court records from the Rodriguez case showed that Sucart introduced Bosch and Rodriguez.

“This is the American justice system, and the key word being justice here, and these are only allegations,” said Jeffrey Cox, a lawyer for Sucart.

Also charged was Juan Carlos Nuñez, 48, a middleman who was believed to have introduced a number of ballplayers to Bosch. When players were suspended by MLB a year ago, some described how Nuñez put them in touch with Bosch.

A lawyer for Nuñez declined to comment Tuesday.

Another former Bosch business partner, Carlos Javier Acevedo, 35, was also arrested and charged with conspiring in the drug case.

Prosecutors said the investigation into Acevedo led them into another case — in which they alleged that Acevedo and others associates had distributed the drug known as Molly, a form of Ecstasy. The DEA made arrests in that case Tuesday too.

BostonGlobe.com complimentary digital access has been provided to you, without a subscription, for free starting today and ending in 14 days. After the free trial period, your free BostonGlobe.com digital access will stop immediately unless you sign up for BostonGlobe.com digital subscription. Current print and digital subscribers are not eligible for the free trial.

Thanks & Welcome to Globe.com

You now have unlimited access for the next two weeks.

BostonGlobe.com complimentary digital access has been provided to you, without a subscription, for free starting today and ending in 14 days. After the free trial period, your free BostonGlobe.com digital access will stop immediately unless you sign up for BostonGlobe.com digital subscription. Current print and digital subscribers are not eligible for the free trial.